Progression of advanced interatrial block to atrial flutter: a prospectively-followed case.

Interatrial block (IAB; P wave > or = 110 ms), commonly associated with left atrial enlargement and its electromechanical dysfunction, is also a significant correlate of atrial tachyarrhythmias. While the arrhythmogenic mechanisms of atrial fibrillation and atrial flutter may indeed differ, there is actually considerably less literature showing evidence of prospective progression of IAB, be it partial or advanced, to atrial flutter. We present a unique case of atrial flutter occurring within months of diagnosis of advanced IAB in an otherwise healthy female to briefly generate our discussion on the possible reasons for this scenario.